/*
 * Artificial Intelligence for Humans
 * Volume 2: Nature Inspired Algorithms
 * Java Version
 * http://www.aifh.org
 * http://www.jeffheaton.com
 *
 * Code repository:
 * https://github.com/jeffheaton/aifh
 *
 * Copyright 2014 by Jeff Heaton
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For more information on Heaton Research copyrights, licenses
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */
package com.heatonresearch.aifh.evolutionary.sort

import com.heatonresearch.aifh.evolutionary.genome.Genome
import com.heatonresearch.aifh.evolutionary.train.EvolutionaryAlgorithm
import java.util.Comparator

/**
 * Sort the gnomes for species.  Sort first by score, second by birth generation.
 * This favors younger genomes if scores are equal.
 */
class SortGenomesForSpecies(val train: EvolutionaryAlgorithm) extends Comparator[Genome] with Ordering[Genome] {

  override def compare(g1: Genome, g2: Genome): Int = {
    val result = train.selectionComparator.compare(g1, g2)
    if (result != 0) {
      return result
    }
    g2.birthGeneration - g1.birthGeneration
  }
}